The Phone OS is still my favourite UI and was incredibly unique when first introduced. Live tiles in an era of pages of icons was way ahead of it's time. The phone hardware was/is great too; the lack of apps destroyed them though
I'm super loyal to the Microsoft Basic mouse. It lasts forever whereas all the Logitech M100's that I've purchased (and I've purchased a lot of them) don't last more than 6 months. Sad!
+1, had a Microsoft Mouse 5000 for the last ~5 years. Good for larger hands, love the smooth scrolling having got used to it. Needs the odd teardown to remove fluff from the optical wheel sensor, I can live with that fine :)